Objective To investigate the correlation between coronary artery calcium score (CACS) and major adverse cardiovascular events (MACE) after percutaneous coronary intervention (PCI) in patients with coronary heart disease, and to evaluate its predictive value. Methods A retrospective analysis was performed on 186 patients with coronary heart disease. Agatston calcium score was calculated before PCI, and patients were followed up for 12 months, divided into MACE group (n＝28) and non-MACE group (n＝ 158) . Multivariate Logistic regression and receiver operator characteristic (ROC) curve were used to analyze the association and predictive efficacy. Results MACE group occurred in 15.05% (28/186). CACS in MACE group was significantly higher than that in non-MACE group (P＜0.05). CACS (OR＝1.010, 95%CI: 1.004～1.016), number of diseased vessels (OR＝10.319, 95%CI: 3.258～ 32.680), and stenosis degree (OR＝1.234,95%CI:1.122～1.357) were independent risk factors (all P＜0.05). The area under the curve (AUC) of CACS for predicting MACE was 0.705, with an optimal cutoff of 362 points (sensitivity 57.14%, specificity 87.34%). Conclusion CACS is positively correlated with post-PCI MACE risk and serves as an independent predictor with moderate predictive value. Preoperative assessment of CACS is helpful in identifying high-risk patients and in formulating clinical decisions.